The starter gear retracts when the power is cut -- the solenoid retracts back into the solenoid housing and the gear is pulled back with it. In other words it will stay engaged as long as you hold the key to S position. The overrun clutch lets the engine run faster than the gear
Failing overrun clutch causes a whizzing or "zing"-ing sound, as it tries to turn the engine but then fails or partially fails
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hear it getting spun and bouncing off the flywheel teeth
A grinding/buzzing sound indicates the teeth on the flyweel are worn to the point the starter gear wont engage but merely grind against the flywheel ring gear. It typically wears in four spots. The engine usually stops in one of four spots unless you force it otherwise for example dumping the clutch after turning off the engine will cause it to stop in a random place (and no grinding at the next startup). The grinding will gradually get worse until it nearly always happens. To check for this, remove the flywheel dust cover (if equipped) or remove the starter and shine a flashlight on the flywheel ring gear, rotate the flyweel and look for a bad spot